Thumbturn for a door lock



FIG. 1 is a front view of a thumbturn for a door lock.

FIG. 2 is a first perspective view of the thumbturn for a door lock of FIG. 1.

FIG. 3 is a second perspective view of the thumbturn for a door lock of FIG. 1.

FIG. 4 is a first side view of the thumbturn for a door lock of FIG. 1; and,

FIG. 5 is a second side view of the thumbturn for a door lock of FIG. 1 that is opposite the first side view of FIG. 4.

The broken lines showing the door lock assembly in the Figures are for illustrative purposes only and form no part of the claimed design. The shade lines in the Figures show contour or the flatness of a surface, and not surface ornamentation. 

CLAIM I claim the ornamental design for a thumbturn for a door lock, as shown and described. 